Electric-arc lamp



(No Model.)

W. H. BARKER.

ELEGTRIO ARC LAMP. No. 408,948. Patented Aug. 13 1889.

William JCBqrIrer by his flfiarneyS, W WM UNITED STATES PATENT ()FFICE.

IVIILIAM H. BARKER, OF LAWVRENCE, KANSAS.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 408,948, dated August13, 1889.

Application filed November 12, 1888.

To all whom it may concern:

Be it known that I, IVILLIAM II. BARKER, a citizen of the United States,residing in Lawrence, Douglass county, Kansas, have invented certainImprovements in Electric-Arc Lamps, of which the following is aspecification.

My invention consists of certain improvements in the construction ofelectric -arc lamps; and one of the main objects of my invention is toso construct such lamps that they will automatically cut themselves outof circuit after being in circuit certain fixed lengths of time, whichwill vary according to different requirements.

Another object of my invention is to so construct the positive -carbon-holding rod that it will be unnecessary for the lamptrimmer to cleanthe rod for the purpose of securing good contact, and so that goodcontact between the movable rod and some fixed portion of the frame mayalways be insured at apoint which is never exposed to the atmosphere.

In the practical establishment of an arelight system it is desirablethat the different lamps should not be left in circuit and the carbonsallowed to burn for longer times than may be provided for in thecontracts, or for longer times than the light is actually needed bycustomers. lamps only for a few hours each night, while others requiretheir lamps to be in circuit for longer periods, and in some cases allnight. For this reason it has been customary to have separate circuitsfor lamps which are to be used different lengths of time, all thethreehour lamps, for instance, being on one circuit, while all thesix-hour lamps, for instance, are on another circuit, no matterwhereabout in the system they may be located.

It is one of the objects of my invention to so construct the lamps thatlamps which are to be used for different lengths of time-as, forinstance, three, five, six, or eight hours at a time-1nay be used on thesame circuit, if desired, and that each lamp will automatically cutitself out of circuit Without leaving any resistance in its place whenits positive carbon has burned a certain length, or, What is the samething, when the lamp has been in use the provided number of hours. Forthis Some customers need their Serial No. 290.590. (No model.)

purpose I provide the positive-carbon-carrying rod with devices atproper points in its length, and combine therewith a cut-out, which,when the rod has descended a certain distance, will short-circuit thelamp out, as hereinafter described.

My present invention includes certain other improvements, which will beset forth in the course of the following description.

In the drawings I have illustrated my improvements as applied to a lampprovided with the well-known 'IhomsomHouston regulating devices but itwill be understood that my invention is applicable to variousconstructions of arc lamps.

In the accompanying drawings, Figure l is a vertical section ofsufficient of an arc lamp to illustrate my invention. Fig. 2 is a planview on the line 1 2, Fig. 1, the sheet-metal casing around theregulating devices being removed. Fig. 3 is a perspective View of thecarbon-holding rod drawn to a larger scale. Fig. 4 is a perspective viewof a contact-lever II. Fig. 5 is a perspective view of a modification,and Fig. 6 is a view of a still further modification.

In setting forth the present invention it willnot be necessary todescribe in detail the construction of the lamp and the regulatingdevices illustrated, for, as I have already said, they are of well-knownconstruction and do not form any essential part of my invention, andthey may be varied as circumstances make desirable. It will suffice,however, to say that in Figs. 1 and 2 of the accompanying drawings A isthe frame of the lamp, having an inclosing-case a for the regulatingdevices, and the upper partof the frame carries the inclosing-tube B forthe positive-carbon-carrying rod, while to the lower portion of theframe are secured the arms a, which carry the negative carbon and globe.(Not shown.)

E are the regulatingmagnets, with the armature e on the pivotedarmature-lever e, and F is the clamp carried by said armaturelever toact 011 the positive-carbon-carrying rod D in the usual manner for theformation of the arc and the feeding of the carbon. The lower end ofthis carbon-carrying rod D is provided with a clamp d for the positivecarbon p, while at its upper end it is pro feed forward.

vided with a brush (1, having spring contact fingers which bear againstthe inside of the conductor-tube G, held centrally within. theinclosing-tube B of the frame by means of insulating-blocks Z) at itsupper and lower ends. This metallic conducting-tube is electricallyconnected with the positive terminal of the lamp and is highly polishedon the inside, so that the contact-brush on the upper part of the carboncarrying rod may move freely thereon and make continuous contact withthe inside of the tube at points which are never exposed to theatmosphere, and conse quently the cleaning of the carbon-carrying rodusually required with ordinary lamps becomes unnecessary.

In the circumference of the carbon-carrying rod I form at the desiredpoint or points notches n, which may or may not extend all around thecircumference of the rod, although I prefer to extend them all the wayaround.

I provide on the frame of the lamp at suitable point an automaticcut-out consisting of a fixed and pivoted contact to operate inconnection with the notches on the rod. The fixed contact is connectedto one terminal of the lamp, while the movable contact is electricallyconnected to the other terminal of the lamp, so that when the contactsmeet the short circuit will be closed and the lamp with itsregulating-coils cut out of circuit, thus leaving in its placepractically no resistance. In the present instance I have shown thefixed contact. II as electrically connected to the binding-post P andprovided with a suitable adjusting-screw h. The pivoted contact consistsof a small bent lever Ii, having a fine edge to bear against the side ofthe carbon rod D and to enter the notch or notches therein when it orthey shall come opposite it. This pivoted contact-lever is acted on byan adjustable push-spring 7t, which tends to press the edge of the leveragainst the edge of the carbon-carrying rod and into the notch ornotches when one presents itself. This pivoted lever is connected to thebinding-post P of the lamp.

The contact-lever II is preferably so arranged in reference to a cam Mor other de vice, which is used to operate the armaturelevcr c and itsclamp 1 so as to release the carbon-carrying rod, that when this cam isturned by its insulated handle m, or otherwise, to free the clamp Faportion of the cam will act on the rear end of the lever II anddisengage its edge from the notch in the carhon-carrying rod I) andallow the latter to Then on returning the handle in and cam I to theirnormal positions the lamp is thrown in to circuit again, and the notchhaving descended below the lever 11 thclamp is thrown into operationagain for another period of time, or until the next notch comes oppositethe movable contact II.

The number of notches in the peripheries of the carbon-carrying rods andtheir distances apart in each rod will vary of course with the lengthsof time which the different lamps containing these rods are intended toburn. In the drawings I have shown the rod D as provided with three ol.these notches at such distances apart that the lamp will burn, say,three hours at a time, for instance, before it is automatically cut outin the manner above described-that is, by the entry of the pivotedcontact ll into the approaching notch in the carbon-carrying rod and theconsequent closing of the short circuit across from one binding-post Pto the other I.

The carbon-carrying rod is shown as cov ered with an insulating-sleeveS, so that the cleaning of this carbon-carrying rod becomes unnecessary,and there can be no contacts or short circuits by the bearing of thepivoted contact-lever H. upon the rod. It should be understood, however,that, if preferred, the bearing-face of the contact-lever ll may beprovided with insulating material in place of that now upon thecarbon-can-ying rod itself. I prefer, however, to provide thecontact-carrying rod D with. the insulating-sleevc, although, if desiredor preferred, another metal cylinder may be slipped over theinsulatingsleeve.

In Figs. 2 and 3 I have shown the notches in the carbon-carrying rod asextending all around its circumference; but this is not necessary, andthe notchesmay be on one side only, so that by turning the notched sidetoward the pivoted contact II the lamp may be arranged to automaticallycut itself out when a certain amount of carbon has been burned, while byturning the rod around, so that the other side is presented to thepivoted contact, the lamp may be arranged to burn until the carbon isexhausted, or, if provided with notches differently spaced, may bearranged to burn for a diiferent number of hours. In Fig. 5 I haveindicated the red as made in a polygonal form with dillt'erently spacednotches on different sides, so that the lamp using such a rod might bearranged to burn for a dilferent number of hours, according to the sizeof the rod which, turned to the pivoted contact-lever II.

The head-piece carrying the brushes 1 may be swiveled to thecarboncarryin grod, or the lamp d at the lower end may be swiveled tothis red.

IVhen the arc lamp is provided with two sets of carbons, onecarboimarrying rod may be provided with one set of notches, while theother carbon-carrying rod may be provided with notches differentlyspaced, so that by using one pair of carbons the lamp may be burned fora certain number of hours, while by turning the current through theother pair of carbons the lamp may be in op eration for anotherdilltn'ent number of hours.

I claim as my invention 1. The combination of the terminals of anelectric-arc lamp with a cut-on t having con tacts one in connectionwith one terminal and the other with the other terminal, and

the positive-carbon-carrying rod having at intervals, corresponding withthe lengths of time the carbon is to burn, means, substantially asdescribed, for closing the cut-out.

2. The combination of the terminals of an electric-arc lamp with acut-out having contacts one in connection with one terminal and theother with the other terminal, and the carbon-carrying rod having atintervals notches into which the movable part of the cut-out can enterto automatically cut out the lamp, substantially as set forth.

3. The combination of the terminals of an electric-arc lamp with acut-out having contacts one in connection with one terminal and theother with the other terminal, and a carbon-carrying rod having atintervals on one side notches into which the movable part of the cut-outcan enter to short-circuit the lamp, substantially as specified.

4. The positive-carbon-carrying rod of an arc lamp having aninsulating-cover.

5. The combination of the terminals of an electric-arc lamp with acut-out having contacts and a carbon-carrying rod having aninsulating-cover with notches at intervals, into which the movable partof the cut-out can enter to short-circuit the lamp, substantially asspecified.

6. The combination of the frame of an arc lamp having a conductor-tubewith the movable carbon-carrying rod having a contactbrush at its upperend and having 011 its main body an insulating-cover.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

WILLIAM H. BARKER.

Witnesses:

HENRY HOWSON, HARRY SMITH.

